Obsidian at Kaman-Kalehöyük

Obsidian is natural glass that forms when volcanic lava with high silica content cools rapidly. Although it only occurs at specific sites, obsidian was valued by ancient civilizations for its various properties – translucency, sharpness, workability. The obsidian from each volcanic site exhibits a unique assemblage of trace elements, which allows scientists and archaeologists to pinpoint the original source of excavated obsidian through instrumental analysis. Determining where materials originate from helps researchers understand ancient trade routes. Most of the obsidian analyzed from Kaman-Kalehöyük comes from Nenezi Dag, Tulce, and Komurcu sites in Central Anatolia, modern-day Turkey. See http://www.busitu.numazu-ct.ac.jp/mochizuki/english/stattk.htm

Conserving obsidian is much like conserving other archaeological glass. The surface is cleaned with ethanol or a solution of water and ethanol. While treating obsidian conservators must be careful of the sharp and delicate edges because obsidian fractures under mechanical pressure with the characteristic conchoidal pattern typical of pure silicates.